Advice on Chainrings

Brocade

Folks,

I have a SRAM Rival groupset with standard chainrings. I would like to change the chain rings to a compact set. Any recommendations ? Also, in terms of compatibility, what do I need to be careful for ?

Finally, if I change to a compact, do I need to change the front derailleur ?

Thanks in advance.

brownleather

You'll need a new chainset for compact rings. BCD is different.

Best bet is go with an SRAM/Truvativ C/set as they take the same BB.

The front derailler will just need to be lower a couple of mm.

Brocade

Thanks.

But do I need new cranks as well ? Can't I just buy the chainrings and replace the chainrings on the existing cranks ?

ride_whenever

no the holes are set at a different radius.

brownleather

If you have a compact crankset (BCD = 110mm) with 53/39 rings, buying compact rings will work.

But if you have a standard crankset (BCD = 130mm) compact chainring @ 110mm BCD won't fit.

Odds on if you have 53/39 you have a 130bcd chainset, so you'll need to get a new chainset too.

Brocade

OK many thanks.